She mentioned that you might be interested in the concretion preservation of early pediocene mammals and other animals recently found at coral bluffs in Colorado.
At this location, in three or four fathoms of water between the Paeu and Vana reefs, there lay some anchors, cannons, and ingots of iron and lead, all caked with limestone concretions.
A sperm whale's colon can bulge to five times its usual diameter to accommodate one of these snowballing concretions, but eventually, it ruptures, killing the whale and releasing a huge butt-pearl of ambergris into the ocean.